The Dewalt DWA4500 4 in. X 1/4 in. X 5/8 in. Masonry Grinding Wheel is designed for quick and clean cuts. This wheel contains two full sheets of fiberglass to extend the life of the wheel and improve safety. The Aluminum Oxide formulation ensures fast cuts. Aluminum Oxide formulation for efficient cuts. Double Layer fiberglass. 1/4 in. thin grinding wheel. 4 in. wheel with 5/8 in. arbor.